Muslim MP says Sydney siege not religious

The only Muslim MP in federal parliament says the Sydney siege tragedy was not religiously-motivated but a criminal act.

Labor MP Ed Husic says society should be careful in cloaking Man Haron Monis's actions under the banner of religion.

"This is not motivated by religion, it's usurped religion for the purpose of a political aim," Mr Husic told Sky News on Thursday.

Monis, a self-proclaimed Islamic cleric, forced his hostages to display Islamic flags against the Lindt Cafe's windows and demanded a flag of terrorist group ISIL be delivered to him during the dramatic 16-hour siege.

And in video messages he forced hostages to record, one said he wanted Australia to know it was under attack from Islamic State.

But Mr Husic said Monis should not be given any more credence because he was aiming to gain notoriety and capture attention.

"What he saw was an opportunity to cause terror and pain to people and he had no regard to human life," Mr Husic said.